wheel size and mod question

[NickHall 0]

New to the forum. Not new to my Mustang. I've had it for 30 years (it was my first car). I've finally decided that I'd like to move more toward a restomod look and am eyeing some wheels/tires. I'd like to put a 275/40r18 on the front. I know, I know...it might be crazy and won't fit in the stock configuration. However, I'm willing to modify it if needed. 

Does anyone here have experience/knowledge regarding what kind of modifications I'd be looking at in order to make that size tire fit? I can roll the fender myself, but would it require more of a flare than a roll? Would I have to modify the valence? 

 

[rwcstang 214]

2 hours ago, NickHall said:

New to the forum. Not new to my Mustang. I've had it for 30 years (it was my first car). I've finally decided that I'd like to move more toward a restomod look and am eyeing some wheels/tires. I'd like to put a 275/40r18 on the front. I know, I know...it might be crazy and won't fit in the stock configuration. However, I'm willing to modify it if needed. 

Does anyone here have experience/knowledge regarding what kind of modifications I'd be looking at in order to make that size tire fit? I can roll the fender myself, but would it require more of a flare than a roll? Would I have to modify the valence? 

 

are you on OE Disc/stock suspension or is it lowered and you have a different brake kit?

if on stock suspension/brakes, other can respond back to this as they've done with 17 or 18 wheels.

2 x 18 x 8 4.5 backspace (Front)
2 x 18  x 9 5.5 backspace (Rear)

Front Tires: 245/40x18

Rears tires:  275/40x18

I have 18x9 (front) and 18x10 (Rear) fr500s,

• Street or Track Front coilovers: https://streetortrack.com/suspension/front-suspension/coilover-system/street-or-track-mustang-front-bilstein-coilover-system
• Vintage venom 13" brake 03 cobra front and rear brake kit, requires me to use 99-04 wheels (there are other kits that keep OW width, like Mustang Steve/StreetorTrack/wilwood
  • my current brake kit uses a 1.25" spacer for the front and a 1/2 for the rear
• Tires: 245/40/18 x 275/35/18 due to the the brand I have, but i suggest going with a 40 series tires all around for comfort, never go low profile if you want to lose the comfort/drive of your car.

if you go wider in the front, you'll need to mod the following.

• trim the ball joint cover on the stamped upper arm or upgrade with a tubular a-arm (slimmer and stronger).
• Wheel spacer or different backspace/offset for the wheel, some are direct fit and no mod needed, it all depends the manufacturer if they do custom offsets of their wheel. 

Hope that helps!

 

 

[Grabber70Mach 110]

Another option is Shaun's (Street or Track) spindles with his front coilovers.

https://streetortrack.com/suspension/front-suspension/spindles/billet-big-spindles

From his webpage:

We are extremely proud to be able to offer our customers our Billet Big Spindle (patent pending).  Offering a 2" drop, verifiable geometry improvements as well as a significant reduction in bump steer over the factory spindle.  3 years of engineering, CAD design and testing have produced a spindle that fits inside a 17" wheel and allows the wheel to clear the upper ball joint and steering arm.  This means you can fit up to 2" of rim and tire further inboard.  No flares required to fit up to a 10.5" rim and a 315 tire up front with only rolled fender lips.

CNC machined, Tig welded, heat treated & powder coated right here in the USA, this spindle is a major upgrade to the original Mustang spindles.  Think about it.  The original cars were designed for bias ply tires that didn't grip very well.  Now, we are using modern radial tires with lots more grip.  The early spindles are prone to breaking under harsh driving conditions with sticky tires.  If you are serious about road racing, open tracking, building a corner carving restomod or pro-touring street machine, you should upgrade your early spindles.

Tire size possibilities - measured on cars with SOT coilover and rolled fender lips:

1965-66 Mustang	1967-68 Mustang	1969-73 Mustang
17x9.5" with 6.25" backspacing & 275/40/17 tires 18x9.5" with 6.25" backspacing & 275/35/18 tires	17x10" with 6.30" backspacing & 295/40/17 tires 18x10" with 6.30" backspacing & 295/35/18 tires	17x10.5" with 6.80" backspacing & 315/35/17 tires   18x10.5" with 6.80" backspacing & 315/30/18 tires